References of "Strivay, David"
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See detailLes matériaux des mosaïques de Germigny-des- Prés
Van Wersch, Line ULiege; Kronz, Andreas; Simon, Klaus et al

in Bulletin du Centre d'Études Médiévales d'Auxerre (2019), Hors-série n°11

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See detailNon-invasive analysis of mural paintings from a Republican house from 1st B.C. in Ostia
Herens, Elodie ULiege; Defeyt, Catherine ULiege; Morard, Thomas ULiege et al

Conference (2018, May 23)

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei ... [more ▼]

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei bucranes, a house of the end of the Republican era discovered on the site of the Schola of Trajan in Ostia. This Domus has undergone several phases of development in the 1st century BC before being destroyed around 20 BC. A new house was immediately rebuilt after a major change from the ground, which allowed exceptional preservation of the decoration system. The results complement our knowledge of Roman painting techniques during the 1st century BC and also provide a comprehensive multidisciplinary approach to the problem of conservation of wall paintings. These two related objectives have been studied using non-destructive testing methods (MA-XRF, FTIR and Raman spectroscopy). The analyzes have been performed in situ using our mobile systems. The different set-ups had to be modified in order to be able to work on horizontal surfaces, specially our XRF scanner. The study of the pictorial layers address various issues in the field of archaeology: what technique has been implemented? Does the same technique was used in both phases of the development of Domus? Do they correspond to the techniques described by ancient writers? These responses are compared to those observed in other sets of murals dating from the 1st century BC. [less ▲]

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See detailMonte Carlo method for gamma spectrometry based on GEANT4 toolkit: Efficiency calibration of BE6530 detector
Guembou Shouop, Cébastien Joel ULiege; Ndontchueng Moyo, Maurice; Nguelem Mekongtso, Eric Jilbert et al

in Journal of Environmental Radioactivity (2018), 189

The combination of gamma-ray spectrometry, the development of related Monte Carlo method and the GEANT4 (GEometry ANd Tracking) toolkit have been developed for gamma spectrometry simulation. The main ... [more ▼]

The combination of gamma-ray spectrometry, the development of related Monte Carlo method and the GEANT4 (GEometry ANd Tracking) toolkit have been developed for gamma spectrometry simulation. The main objective was to validate simulation models of broad energy germanium (BEGe) detector geometry built in our laboratory (BE6530 model). Monte Carlo simulation of the geometry of BE6530 detector for efficiency calibration was carried out with GEANT4 toolkit. The simulated efficiencies curves using MC were compared with experimental results. Measurement uncertainties for both simulation and experimental estimations of the efficiency were assessed in order to see whether the consequences of the realistic measurement fall inside adequate cut-off points. The validation of the simulation was carried out by experimentally estimating the activity concentration in a reference sample and the comparison showed good correlation between experimental and simulation. Therefore, from the outcomes of this study, it can be concluded that Monte-Carlo simulation is a helpful, reasonable option that additionally gives more prominent adaptability, greater flexibility, precision and accuracy, and gained time when determining the detector response and efficiency in routine of environmental radioactivity monitoring. [less ▲]

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See detailNicolas Schöffer’s collection: from the artist’s studio to the museum
D'Haenens, Manon ULiege; Verbeeck, Muriel ULiege; Strivay, David ULiege

in Rivenc, Rachel; Bek, Reinhard (Eds.) Keep it moving ? Conserving kinetic art: Proceedings from the meeting organized by the Getty Conservation Institute, the ICOM-CC Modern Materials and Contemporary Art Working Group, and Museo del Novecento (2018, March)

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See detailDe bois, de pierre, de terre…et de verre. Approche de l’approvisionnement des chantiers alto-médiévaux à travers le cas de la mosaïque du baptistère de Nevers.
Van Wersch, Line ULiege; Neri, Elisabetta; Chene, Grégoire ULiege et al

Conference (2018)

Les découvertes de verre architectural qui se sont multipliées ces dernières années lèvent peu à peu le voile sur le rôle joué par de ce matériau dans les édifices alto-médiévaux. Les églises possédaient ... [more ▼]

Les découvertes de verre architectural qui se sont multipliées ces dernières années lèvent peu à peu le voile sur le rôle joué par de ce matériau dans les édifices alto-médiévaux. Les églises possédaient de véritables vitraux et le verre pouvait être incrusté dans les murs et les sols où il jouait un rôle dans la réflexion de la lumière. Dès lors, le besoin croissant de verre architectural a pu contribuer aux innovations techniques dans l’artisanat verrier du nord-ouest de l’Europe ainsi qu’à la mise en place de réseaux d’approvisionnement spécifiques en fonction des chantiers de construction. Attribuées au décor VIe siècle, les tesselles mises au jour lors des fouilles de la cathédrale de Nevers, dans le baptistère, sont un témoignage du début de ce processus. Les cubes sont majoritairement réalisés en verre, opaque et coloré ou incolore et recouvert d’une feuille d’or. Comme certains d’entre eux étaient encore insérés dans du mortier portant des traces de polychromie, leur attribution a une mosaïque pariétale est assurée. L’étude de ces objets et leur analyse en PIXE-PIGE et en raman, nous a permis d’identifier les matières premières et les techniques utilisées pour leur mise en œuvre. La comparaison avec des édifices contemporains a mis en exergue des points communs et les particularismes propres au site de Nevers, nous permettant de proposer une hypothèse pour l’approvisionnement des matériaux nécessaires à la décoration du baptistère. Cette étude révèle ainsi l’importance d’un chantier de mosaïque pariétale et la complexité des relations qu’il demande. [less ▲]

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See detailRecherches récentes sur le site de Germigny-des-Prés (Loiret, France).
Van Wersch, Line ULiege; Hocquet, François-Philippe ULiege; Strivay, David ULiege et al

Conference (2018)

Restauré au XIXe siècle, l'église de Germigny-des-Prés est actuellement la seule au nord des Alpes à abriter des mosaïques alto-médiévales. L’édifice de culte, bâti au début du IXe siècle, faisait partie ... [more ▼]

Restauré au XIXe siècle, l'église de Germigny-des-Prés est actuellement la seule au nord des Alpes à abriter des mosaïques alto-médiévales. L’édifice de culte, bâti au début du IXe siècle, faisait partie de la villa de Théodulphe, proche conseiller de Charlemagne, abbé de Fleury et évêque d’Orléans. Ce site est donc exceptionnel à plus d’un titre. D’une part, l’église est une des plus anciennes de France et, en dépit de restaurations, elle reste un témoignage singulier de l’architecture religieuse alto-médiévale. D’autre part, ses mosaïques nous permettent d’aborder ce type de décoration et plus largement le verre, matériaux rares pour cet époque. Enfin, le site devrait receler les vestiges d’une villa carolingienne dont la réalité matérielle pose encore de nombreuses interrogations. Depuis trois ans, en collaboration avec une équipe internationale, des recherches utilisant des méthodes diverses ont été entreprises. Les mosaïques ont fait l’objet d’un premier examen macroscopique et d’analyses pXRF In situ pour distinguer les parties originales de la restauration du XIXe siècle. 15 échantillons de verre ont ensuite été analysés en EMP-WDS et LA-ICP-MS afin d'identifier leurs matériaux, recettes et provenances. Malgré la restauration plus vaste qu'on ne le pensait auparavant, des parties originales subsistent sur la voûte orientale. Si, des tesselles colorées antiques ont été réutilisés, les cubes couverts d’or et d’argent proviennent d'une production originale. Aucune correspondance n’existant dans le monde italien et byzantin, ils pourraient être issus d’une production spécifique, peut-être régionale. Des prospections géoradars ont été effectuées sur le site afin de localiser de potentiels vestiges alto-médiévaux. Elles ont mis en évidence l’existence de structures en différents emplacements. A l’intérieur du bâtiment, elles ont identifié l’abside occidentale confirmant la restitution du plan original proposé en 1930. A l’extérieur, elles ont permis de détecter les zones sur lesquelles devraient se concentrer les recherches archéologiques. Enfin, un scan 3D a permis un relevé précis du bâtiment. Il sera utilisé pour la gestion de l'information et la visualiser des résultats des recherches que nous espérons poursuivre sur le site de Germigny-des-Prés. [less ▲]

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See detailThe carolingian site of Germigny-des-Prés (Loiret, France), micro and macro-scales methods for the identification of a mosaic production.
Van Wersch, Line ULiege; Hocquet, François-Philippe ULiege; Strivay, David ULiege et al

Poster (2018)

The church of Germigny-des-Prés is one of the oldest in France. It holds the only early medieval mosaics preserved north of the Alps, ordered by Theodulph, close counselor of Charlemagne, at the beginning ... [more ▼]

The church of Germigny-des-Prés is one of the oldest in France. It holds the only early medieval mosaics preserved north of the Alps, ordered by Theodulph, close counselor of Charlemagne, at the beginning of the 9th century AD to decorate the oratory of his villa 1. Restored in the 19th century, it still conserved a part of the original material. These tesserae are a great opportunity to reach the glass from the early Middle Ages, period of change for glass production. Moreover, this site could have hold a mosaic workshop and it could be the first settlement of this type ever discovered 2. In situ, a macroscopic exam and pXRF analyses done on the tesserae from the vault and arches allow to distinguish original material and restored area. 15 glass samples were analysed using EMP-WDS and LA-ICP-MS in order to identify their materials and techniques as well as their origins. A 3D scan of the building makes possible to quantify accurately the materials, to manage the information and to view the results. Finally, ground penetrating radar prospections were done on the site in order to locate a potential workshop. The concentrations of lead, potassium and iron allow us to distinguish the early medieval tesserae from the new ones. Thanks to this, the original part of the mosaic can be precisely differentiated from the restoration of the 19th century that is vaster than previously thought. Still, the figures of the vault appear to be original. The analysed cubes show that some were re-used roman tesserae but the ones with gold and silver, the most numerous in the mosaic of the vault, come from an original production, specific to this site. Structures were found by prospections in different locations around the church and excavations will now take place in order to identify this remains and a potential workshop. Acknowledgements: to the council of Germigny-des-Prés and the DRAC Centre Val-de-Loire for the research authorizations. The missions were financed by the FRS-FNRS, The Comhaire prize of the foundation Roi Baudouin and by ARCHEA. 1 A. Freeman, P. Meyvaert, Gesta (2001), 125- 139. 2 L. James, E. Soproni, B. Bjornholt, in «Mosaics by numbers, (2013), 310-328. [less ▲]

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See detailThe Glass Tiles from Saint-Sauveur (Burgundy, France)
Van Wersch, Line; Gratuze, Bernard; Mathis, François et al

in Journal of Glass Studies (2018), 60

Eight glass tiles from Saint-Sauveur in Burgundy, which are considered to be of early medieval date, were investigated. These tiles, which are in a good state of preservation, are 10 centimeters square ... [more ▼]

Eight glass tiles from Saint-Sauveur in Burgundy, which are considered to be of early medieval date, were investigated. These tiles, which are in a good state of preservation, are 10 centimeters square and nearly two centimeters thick. They are made of dark glass with red and white glass inlays. These glass tiles have often been compared with those from the early medieval monastery of Corvey in Germany. However, because they lack an archaeological context, their date is uncertain. PIXE-PIGE and LA-ICP-MS analyses revealed a wood-ash glass composition, close to that of High Lime Low Alkali (HLLA) glass dating from the 14th century and later. The authors’ trace analyses confirm the more recent dating because the elements associated with cobalt reveal sources used only from the 16th century. [less ▲]

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See detailRevealing Gauguin’s practice: multi-analytical approach of the Portrait de Suzanne Bambridge
Defeyt, Catherine ULiege; Van Vyve, E.; Leen, F. et al

in Heritage Science (2018), 6(1),

The Portrait de Suzanne Bambridge (1891) is the first oil painting executed by Paul Gauguin (1848–1903) in Tahiti. A comprehensive material study of the painting by means of MA-XRF, Raman and FT-IR ... [more ▼]

The Portrait de Suzanne Bambridge (1891) is the first oil painting executed by Paul Gauguin (1848–1903) in Tahiti. A comprehensive material study of the painting by means of MA-XRF, Raman and FT-IR techniques has been conducted to understand Gauguin’s practice. The obtained results allowed collecting unexpected material evidences, which suggest restoration and subsequent addition made by Gauguin himself. Moreover relevant compositional information has been provided that has influenced the decision-making process during the restoration of the painting as the removal of the old varnish and the overpaints, dating from undocumented past treatments, turned out to be much more complicated than expected. While X-ray radiography and multi-spectral imaging methods could not give sufficient information, overpaints and original paint layers have been distinguished through this multi-analytical approach. © 2018, The Author(s). [less ▲]

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See detailDiscovery and multi-analytical study of the last missing quarter from René Magritte’s La pose enchantée
Defeyt, Catherine ULiege; Herens, Elodie ULiege; Leen, F. et al

in Heritage Science (2018), 6(1),

The last missing quarter of La pose enchantée, a 1927 Magritte’s oil painting disappeared in 1932, has been finally found beneath Dieu n’est pas un saint, picture painted by the Belgian surrealist between ... [more ▼]

The last missing quarter of La pose enchantée, a 1927 Magritte’s oil painting disappeared in 1932, has been finally found beneath Dieu n’est pas un saint, picture painted by the Belgian surrealist between 1935 and 1936, conserved at the Brussels Magritte Museum (Royal Museums of Fine Arts of Belgium) (inv. 11681). The in-depth study conducted on Dieu n’est pas un saint by means of non-invasive and complementary imaging and analytical techniques has allowed formulating substantiated conclusions regarding this double painting. On the one hand, the routine imaging methods, including XRR, IRR and digital microscopy, have delivered a comprehensive outcome regarding the transformation process of the right top part of La pose enchantée into the current composition. On the other hand, the pigments used for both the visible and the hidden composition have been characterized through the MA-XRF analysis of the whole picture and punctual Raman measurements. Additionally, the present paper proposes a virtual colorization of La pose enchantée, which has been build on the basis of the overall material evidences collected about the right top part lying beneath Dieu n’est pas un saint. © 2018, The Author(s). [less ▲]

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See detailInter-techniques comparison of PIXE and XRF for Lake sediments
El Ouahabi, Meriam ULiege; Chene, Grégoire ULiege; Strivay, David ULiege et al

in Journal of Analytical Atomic Spectrometry (2018), 33(883 - 892),

In this paper we describe a validation procedure for chemical analysis of major elements and some minor elements as Sr, Cr, Ni, Zn and Zr in heterogeneous geological sediments. The procedure applies two ... [more ▼]

In this paper we describe a validation procedure for chemical analysis of major elements and some minor elements as Sr, Cr, Ni, Zn and Zr in heterogeneous geological sediments. The procedure applies two distinct techniques (PIXE and XRF) to the analysis of sediments. In this work an inter-technique comparison of the heterogeneous lacustrine sediments from the Amik Lake in the vicinity of the Roman city of Antioch (SE, Turkey) was carried out. Dried raw samples and with the addition of linking powder were analyzed using PIXE performed on the “Arkeo” beam line of the University of Liège AVF-Cyclotron and XRF (University of Liège). The aim of this work was to compare PIXE and XRF analysis with the set-ups routinely in use in the two laboratories. The purpose was also to determine the best combination of techniques and sample preparation protocol to be applied for heterogeneous sediments and the main elements of interest for each specific technique. The results are in agreement among the two techniques, with discrepancies concerning almost lighter and minor elements. These differences are related mainly to the texture of the sediments and the intrinsic features of the XRF and PIXE techniques. Major and selected minor elements are sensitive to the grain-size and the porosity of the samples. However, the accuracy of both XRF and PIXE requires the reduction of the grain-size or addition of linking powder to the sediments to fill the voids in order to increase the intensities of both lighter and minor elements. The results demonstrate the critical importance of sample treatment prior to analysis as well as the necessity of several measurement points and replicates to ensure the accuracy of the PIXE results. [less ▲]

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See detailNew insights on the Picasso’s Blue Period painting La famille Soler through non-invasive imaging and analytical techniques
Defeyt, Catherine ULiege; Walter, Philippe; Rousselière, Hélène et al

in Studies in Conservation (2018)

The material study of La Famille Soler through non-invasive imaging, molecular, structural and elemental techniques, permitted a relevant re-examination of this singular blue period painting, which is ... [more ▼]

The material study of La Famille Soler through non-invasive imaging, molecular, structural and elemental techniques, permitted a relevant re-examination of this singular blue period painting, which is considered as the earliest Picasso’s version of Le déjeuner sur l’herbe by E. Manet. On the one hand, it was concluded that the underlying landscape painted by Vidal in 1903 referred to Manet’s masterpiece. On the other hand, it was assumed that the cubist sketch undertaken by Picasso in 1912, prior to the current blue background, consists of an uncompleted transformation of Vidal’s landscape into synthetic cubism. Additionally, the main pigments associated to the underlying compositions were successfully identified. [less ▲]

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See detailLight Induced Super-Hydrophilicity in Niobium and Tantalum Oxides Thin Films
Henry, Théo ULiege; Bonsague, Fabio; Dubreuil, Olivier ULiege et al

Poster (2017, July)

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are ... [more ▼]

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are wide and numerous:[2] self-cleaning surfaces, anti-fogging, anti-bacterial, water and air purification, microfluidics…Nowadays, a research emphasis is on relatively low energy bandgap semiconductors, targeting a higher efficiency under solar irradiation or more precisely in the near UV and low-end of the visible spectral range. Here, however, we report UV-induced superhydrophilicity in metal oxides thin films showing a relatively high transparency in the UV. Reactive ion beam sputtering (IBS) was used to deposit niobium, tantalum and titanium oxides thin films with thickness ranging from 10 nm to 120 nm on fused silica substrates at room temperature. Contact angle measurements were performed for progressively increasing UV doses and also as function of elapsed time after the termination of the exposure in order to investigate the UV-induced hydrophilicity and recovery behavior of tantalum and niobium oxide thin films in comparison to that of titanium oxide deposited in analogous conditions. [less ▲]

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See detailGeant4 code for gamma spectrometry measurement: a toolkit for Nuclear, Medical, Astronomical and High Energy Physics
Guembou Shouop, Cébastien Joel ULiege; Ndontchueng Moyo, Maurice; Nguelem Mekongtso, Eric J. et al

Scientific conference (2017, June)

In the Monte Carlo method, quantities of interest for the application are calculated through statistical sampling of interaction processes. Gamma spectroscopy is a widely used technique, well-illustrated ... [more ▼]

In the Monte Carlo method, quantities of interest for the application are calculated through statistical sampling of interaction processes. Gamma spectroscopy is a widely used technique, well-illustrated by the following list of examples: Environmental Radioactivity Monitoring, nuclear industry, geochemical investigation, and astrophysics. Most radioactive sources produce gamma rays, which are of various energies and intensities. Geant4 (for GEometry ANd Tracking) is a platform for the simulation of the passage of particles through matter, using Monte Carlo methods. The GEANT4 toolkit allows the simulation of the following physical processes: the photo-electrical effect, the Compton Effect, the electron-positron pairs generation and the Rayleigh diffusion. Our study shows the combination of gamma spectrometry, development of related Monte Carlo equation and the presentation of the Geant4 toolkit for gamma spectrometry simulation (simulation of the interaction of gamma photon through matter). It is clearly found, at the end of this study, that Monte-Carlo simulation is a useful, inexpensive alternative that also provides greater flexibility and gained time when determining the detector response and efficiency during an environmental monitoring. [less ▲]

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See detailNon-Invasive Analysis of Mural Painting from a Late-Republican House (1st century B.C.) in Ostia
Strivay, David ULiege; Herens, Elodie ULiege; Morard, Thomas ULiege et al

Conference (2017, May)

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei ... [more ▼]

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei bucranes, a house of the end of the Republican era discovered on the site of the Schola of Trajan in Ostia. This Domus has undergone several phases of development in the 1st century BC before being destroyed around 20 BC. A new house was immediately rebuilt after a major change from the ground, which allowed exceptional preservation of the decoration system. The results complement our knowledge of Roman painting techniques during the 1st century BC and also provide a comprehensive multidisciplinary approach to the problem of conservation of wall paintings. These two related objectives have been studied using non-destructive testing methods (MA-XRF, FTIR and Raman spectroscopy). The analyzes have been performed in situ using our mobile systems. The different set-ups had to be modified in order to be able to work on horizontal surfaces, specially our XRF scanner. The study of the pictorial layers address various issues in the field of archaeology: what technique has been implemented? Does the same technique was used in both phases of the development of Domus? Do they correspond to the techniques described by ancient writers? These responses are compared to those observed in other sets of murals dating from the 1st century BC. [less ▲]

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See detailNon-invasive analysis of mural paintings from a late-Republican house in Ostia
Strivay, David ULiege; Morard, Thomas ULiege; Herens, Elodie ULiege et al

Conference (2017, April 21)

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei ... [more ▼]

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the characterization of materials. The project focuses on the wall paintings of the Domus dei Bucrani - a house of the end of the Republican era discovered on the site of the Schola del Traiano in Ostia. This domus has undergone several phases of development in the 1st century BC before being destroyed around 20 BC. A new house was immediately rebuilt after a major change from the ground, which allowed exceptional preservation of the decoration system. The results complement our knowledge of Roman painting techniques during the 1st century BC and also provide a comprehensive multidisciplinary approach to the problem of conservation of wall paintings. These two related objectives have been studied using non-destructive testing methods (MA-XRF, FTIR and Raman spectroscopy). The analyses have been performed in situ using our mobile systems. The different set-ups had to be modified in order to be able to work on horizontal surfaces, specially our XRF scanner. The study of the pictorial layers address various issues in the field of archaeology: what technique has been implemented? Does the same technique was used in both phases of the development of the domus? Do they correspond to the techniques described by ancient writers? These responses are compared to those observed in other sets of murals dating from the 1st century BC. [less ▲]

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See detailDiscovery of a woman portrait behind La Violoniste by Kees Van Dongen through hyperspectral imaging
Herens, Elodie ULiege; Defeyt, Catherine ULiege; Walter, Philippe et al

in Heritage Science (2017), 5(14),

Despite the fact that Kees Van Dongen was one of the most famous painter of the 20th century, only little information about his palette and his technique is available. To contribute to the ... [more ▼]

Despite the fact that Kees Van Dongen was one of the most famous painter of the 20th century, only little information about his palette and his technique is available. To contribute to the characterization of Van Dongen's painting materials, La Violoniste, painted by the artist around 1923, has been analyzed by using three complementary techniques: macro X-ray fluorescence (MA-XRF), Raman spectroscopy and hyperspectral imaging. The elemental repartition given by MA-XRF and the results obtained thanks to Raman spectroscopy help us to complete the identification of pigments contained in La Violoniste (lead white, iron oxides, cadmium yellow, vermilion, Prussian blue, titanium white, ultramarine, a chromium pigment and carbon black) while the results obtained via hyperspectral imaging reveal a hidden woman portrait. Besides the fact that Kees Van Dongen was particularly renowned for his female portraits, this hidden composition presents obvious stylistic similarities with the well-known portraits produced by the artist during his Parisian stay (starting from 1899). Thanks to Raman spectroscopy, visual examination and MA-XRF, we show that the original background contains ultramarine, the hidden portrait's clothes are probably made of the same colour as the present violinist's dress and her carnation contains zinc, contrary to the violinist's flesh which is mainly made of lead white. [less ▲]

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See detailAssessment of natural radioactivity and associated radiation hazards in sand building material used in Douala Littoral Region of Cameroon, using gamma spectrometry
Guembou Shouop, Cébastien Joel ULiege; Ndontchueng Moyo, Maurice; Chene, Grégoire ULiege et al

in Environmental Earth Sciences (2017), 76(164),

Twenty-four sand samples were collected from different sand quarries from Douala Littoral Region (Wouri, Dibamba, Mungo and Docteur Anse rivers and Atlantic Sea) along the Guinea Golf. These samples were ... [more ▼]

Twenty-four sand samples were collected from different sand quarries from Douala Littoral Region (Wouri, Dibamba, Mungo and Docteur Anse rivers and Atlantic Sea) along the Guinea Golf. These samples were investigated using gamma-ray spectrometry system. Highest values of 226Ra, 232Th and 40K measured specific activities expressed in Bq Kg−1 units were, respectively, 146.7 (in Youpoue–Bamenda 2) 102.9 (in Village 1) and 928 (in Northern Akwa 6) while the lowest values were found to be, respectively, 11.8 (in Northern Akwa 6), 8.0 (in Bonaberi–Bonamikano 4) and 54.0 (Youpoue 3). The potential radiological hazards parameters were assessed by calculating successively radium equivalent activity (Raeq), outdoor absorbed gamma dose rate (Dout), annual effective dose rate, internal hazard (Hin) and external hazard (Hex) indices and alpha and gamma index from using those sand in the construction of dwellings and large buildings. Results obtained show that annual dose absorbed by inhabitants due to sand construction use in Douala is below 1.0 mSv year−1. Therefore, most of the types of sands studied and incorporated in constructions appear to be safe as building material. The outputs from this research will be useful to assess the radiation hazards of sand building material in humans and to initiate a sand database together with a radiological map of the area at stake. [less ▲]

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